Anatomy Made Easy MSS هذا الملف يشمل تفريغ المحاضرة 10 المحاضرة 12 ابتداء من صفحة 13 وتفريغ part #9 Done By : Isra a Aweidah Edited by: AWN Academic Team
Everything is included ( the drs slides in addition to the script no 10 ) It seems to be a tough one but I tried my best to make it as easy as I could.. Get started and let the battle begin
THE I N D E X : Muscles of the upper limb : Muscles that cross the shoulder joint Muscles that cross the elbow joint : Anterior compartment (forearm flexors ) Posterior compartment (forearm extensors) Anterior forearm muscles : Superficial Deep Lastly,some additional notes
Muscles of the upper limb (Mentioned in previous parts) Muscles that cross the shoulder joint : 1. The biceps brachii 2. Coracobrachialis
A transverse section showing anterior and posterior compartments of the arm :
The Anterior Forearm Muscles (Anterior compartment) 1- Superficial Compartment: a- Flexor Carpi Radialis b- Flexor Carpi Ulnaris c- Palmaris Longus d- Pronator Teres Flexor Digitorum Superficialis (the doctor considers it as a intermediate group so we will be left with 4 muscles for the anterior superficial compartment)
All these muscle which are located in the anterior aspect of the forearm pass down to either the lateral side of the radius or the lateral side of the ulna,and they usually pass underneath the retinacula (flexor retinaculum), so what is the retinacula??
The retinacula :it is a thick connective tissue ligament, since these muscles are long and there origin is usually on the medial epicondyle,they have to cross along way down to their action(the digits or the lateral and medial side of the hand ) so the action will be little and weak and here comes the role of this retinacula and this the base of the lever system. What s the lever system?? the doctor didn t explain it clearly so here is a brief summary gathered fromtortora
lever is a rigid structure that can move around a fixed point called a fulcrum a lever is acted on at two different points by two different forces: the effort,which causes movement,and the load or resistance,which opposes movement
Example for this is the muscle and its action the biceps brachii flexing the forearm at the elbow joint. the elbow is the fulcrum. The weight of the forearm plus the weight of the object in the hand is the load. The force of contraction of the biceps brachii pulling the forearm up is the effort. Motion occurs when the effort applied to the bone at the insertion exceeds the load
Levers are categorized into three types according to the positions of the fulcrum, the effort,and the load: 1- The fulcrum is between the effort and the load in first-class levers 2- The load is between the fulcrum and the effort in second class levers 3- The effort is between the fulcrum and the load in third-class levers
If you have the force which is the muscle and the holding (fulcrum) which is the retincula in the wrist area in the middle and the weight is in the hand, this is first class lever ( this will produce strong pulling force and it resembles the seesaw). But, if we removed the weight to become between the muscle and the retinacula it is a second class lever.the same idea as changing the tires of the car.
Now,the retinacula is present in the anterior aspect of the hand and covers most of the muscles of the anterior compartment of the forearm.they will pass underneath it except for the Palmaris longus but why?
Because it has its own lever system,it will continue by its own to the hand as aponeurosis (palmar aponeurosis) which is fixed on the proximal end of every first phaleneges of the hand. so now you have the force (muscle) then the hand (weight) then the (fulcrum) and it is the only muscle that has adifferent arrangement of distribution of the component of the lever system compared to all other muscles of anterior compartment that pass underneath the reticula.
NEW Flexor Retinaculum: a very thick aponeurotic membrane that holds the muscles in their position and also provide for each tendon of those muscles that comes from the forearm a tunnel. In addition it protect nerves that comes to the hand and protect certain arteries such as ulnar artery. Flexor Retinaculum has nothing to do with Palmaris Longus, it doesn t send any fascia or any attachment to Longus so the Longus is very mobile and superficial muscle and when you grab your hand you can palpate the muscle at the level of the wrist.
Let s Go back to theanterior superficial forearm muscles
Pronator teres laocated on the corner of the forearm and covered partially by the biceptal apponuoiurosis
NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Flexor Carpi radialis NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Flexor Carpi Ulnaris NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Palmaris Longus NEW Origin Insertion Medial epicondyle of humerus Anterior aspect of the Distal flx.retinaculum and Palmar aponeurosis Action Nerve supply flx.the wrist, and tightens the palmar.aponeurosis Median nerve (c6,c7)
Flexor Digitorum Superficialis NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
NEW From lateral to medial Flexor carpi radialis, palmaris longus, and flexor carpi ulnaris.
Palmaris longus has a different story, it comes from the medial epicondyle, it is a thin muscle and more superior than the other muscles, and all the muscles except the Palmaris Longus passes below the Flexor retinaculum where the Palmaris Longus passes above it.
When Palmaris Longus passes above the Flexor retinaculum it will forms a triangular shape at the palm called Palmar aponeurosis and then Palmar aponeurosis divides and goes to the four digit and do attachment to the base of the four fingers. These ligaments that are send from the palmar aponeurosis to the fingers are called superficial transverse ligament of the palm. As you can see the Palmar aponeurosis covers most of the palmar surface between the thener and the hypothenar group of muscles that are located below the thumb and the little finger. NEW
Deep Anterior Compartment of the Forearm 1- Flexor Digitorum Profundus 2- Flexor Pollicis Longus 3- Pronator Quadratus
Flexor Digitorum Profundus NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Flexor Pollicis Longus NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Pronator Quadratus NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Here are Some general notes : All muscles of the anterior compartment of the arm originate from the medial epicondyle of the humerus except the deeper region. PronatorTeres has a totally different insertion which is Middle of lateral surface of radius compared with the others that inserts in the hand. as for its action the main one is pronation but it also help the anterior compartment to complete and perform their action.
Palmaris longus : it originate from the same area but it then mingles and pass anterior to the retinacula and complete with a triangular region of the palm which is called palmar aponeurosis. This apeoneurosis can be palpated easily by flexing your fingers to your hand If you make a fest then pressing tightly on the wrist joint you won t be able to open your hand because the aponeurosis and the extensor muscles will be deficit and can tperform their action.
The intermediate muscle compartment is called Flexor Digitorum Superficialis this muscle has 3 origins but why is that?? Since it is a powerful superficial flexor of the palm on the wrist joint,it will work together with the deep muscle (flexor digitorum profundus).the wide origin of the superfacilis will give it more force.
The tendon of the superfacialis are anterior to those of the profudus and their insertion is before that of the profudus also notice the innervations (median nerve) W hy the superfacialis has to have bigger and wider origin rather than other muscles??
the insertion of the profunds :Base of the distal phalanx of digits 2-5. the insertion of superfacialis : Bodies of middle phalanges of digits 2 5. tendons of the superfacialis will make a bifurcation or split so that it can pass on each sides of the tendons that belong to the profundus because the profundus tendon goes all the way down. so that it can provide more force for its tendons to produce its action.
When you are flexing the distal phalynges of any digit you use the flexor digitorum profundus which is the more deep one. the main action of the superfacialis is Flexion middle phalanges at proximal interphalangeal joints.
Notice how it goes on the anterior aspect of the ulna and interosseous membrane all the way down through the carpal tunnel.which is covered by the second layer of the flexor retinacula. when you look at the retinacula -in transverse section - you will see that it has 3 compartments and that s why when we study muscles, we study them as 3 compartment depending on how they pass through the retinacula Flexor D igitorum Profundus Carpal tunnel
As for flexor pollicus longus sometimes it s part of the flexor digitorum profunds but you might be able to separate it in dissection by dividing them because they are usually enveloped in one fascia. As for the Pronator Quadratus it passes from one bone to another (from ULNA TO RADIUS) and it s situated above the retinacula ( most of the tendons that pass to the hand will pass above this muscle)
superficial Muscles Posterior muscle compartment of the forearm: {2 layers} Deep Muscles
Forearm Muscles- superficial Posterior Compartment: 1) Anconeus 2) Brachioradialis 3) Extensor Carpi Radialis Brevis (short) 4) Extensor Carpi Radialis Longus (long) 5) Extensor Carpi Ulnaris 6) Extensor Digiti Minimi 7) Extensor Digitorum -All (the deepest one)
Posterior Forearm Muscles: These muscles are primarily extensors of the wrist and fingers.
Origin Insertion Action Lateral epicondyle of humerus. *NOTE: Origin of anterior forearm muscles the medial epicondyle (mainly). Origin of posterior forearm muscles the lateral epicondyle (mainly). Lateral surface of olecranon and superior part of posterior surface of ulna -Assists triceps in extending forearm -abducts ulna during pronation. -stabilizes elbow joint. Innervation Radial nerve (C7, C8 and T1) Arterial Supply Middle collateral branch of deep brachial artery; Recurrent interosseous artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Notice the origin & insertion: Notice the action:{helping triceps in EXTENDing the forearm}.
Origin Insertion Proximal 2/3 of lateral supracondyle ridge of humerus. Lateral surface of distal end of radius Action Innervation Arterial Supply Flexes forearm. Radial nerve (C5, C6 and C7). Radial recurrent artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES From its name; brachio comes from the upper lateral aspect of lateral epicondyle (supracondyle ridge). Radialis goes to the distal lateral surface of radius.
Brachioradialis is a big bulky muscle, it s a landmark for the separation between anterior and posterior forearm muscles. It s seen laterally but don t confuse it with the anterior muscles. H ow to differentiate between anterior & posterior muscles? Most of superficial anterior muscles come from the medial aspect of the forearm, while the muscles that come from the lateral aspect belong to the posterior compartment (as Brachioradialis).
Lateral epicondyle Origin Lateral epicondyle of humerus. Insertion Base of 3rd metacarpal Action Extend and abduct hand at wrist joint. Innervation Deep branch of radial nerve (C7 and C8). 3 rd metacarpal base Arterial Supply Radial artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Lateral supracondyle Origin Lateral supracondyle ridge of humerus Insertion Base of 2nd metacarpal Action Extend and abduct hand at wrist joint (the same function as extensor carpi radialis brevis). Innervation Radial nerve (C6 and C7) 2 nd metacarpal base Arterial Supply Radial artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Origin Lateral epicondyle of humerus and posterior border of ulna Insertion Base of 5th metacarpal Action Extends and adducts hand at wrist joint. (opposite to the extensor carpi radialis longus\brevis in the adduction/ abduction). Innervation Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) Arterial Supply Ulnar artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
From lateral supracondyle 2 nd metacarpal base From lateral epicondyle and posterior border of ulna 5 th metacarpal base From lateral epicondyle 3 rd metacarpal base
So both extensor carpi radialis longus & extensor carpi radialis brevis have the same action extend & abduct the hand at wrist joint. But extensor carpi ulnaris has the opposite action extend & adduct the hand at wrist joint. Mnemonic: عبد راضي بحياته عبد= Abduct راضي= Radialis Mnemonic: الجو شوب قد النار :/ قد= Adduct النار= Ulnaris So extensor radialis (longus\brevis) = extend & abduct. so extensor ulnaris = extend & adduct.
Easily seen posteriorly without removing any muscle,(unlike the flexor digitorum which is very deep muscle anteriorly). Origin Insertion Action Lateral epicondyle of humerus Extensor expansions of medial four digits -Extends medial four digits at metacarpophalangeal joints. -Extends hand at wrist joint Innervation Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) Arterial Supply Interosseous recurrent and posterior interosseous arteries NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Notice its action: Extending medial four digits (at metacarpophalangeal joints). Extending hand (at wrist joint). ( ) (medial four digits)
Extensor digiti minimi NEW Origin Insertion Action Innervation Lateral epicondyle of the humerus extensor expansion of the 5th digit ext.of 5th digit at MC, PIP, ext of wrist when little finger in extension PIN (c7,c8)
Forearm Muscles Deep Posterior Compartment: * Abductor Pollicis Longus * Extensor Indicis * Extensor Pollicis Brevis * Extensor Pollicis Longus * Supinator (will do the suponation of the forearm). -These muscles mainly will act on the thumb. -They are covered by the extensor digitorum muscle and extensor carpi Radialis longus\brevis,but can be seen at the lateral lower end of the hand posteriorly. So pronators are at anterior compartment. Suponators are at the posterior compartment.
Forearm Muscles Posterior Compartment: These muscles are primarily extensors of the wrist and fingers. Extends from the ulna into the radius, to supinate the forearm. (The most inferior). For the origin & insertion of these muscles; they come from the ulnar side into the radial side,so according to the anatomical position they are diverged from the medial intothe lateral side of the forearm,toward the thumb.
Origin Has 2 heads: -Oblique head: bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals. -Transverse head: anterior surface of body of 3rd metacarpal 3 rd metacarpal Insertion Medial side of base of proximal phalanx of thumb. Action Draws 1st metacarpal laterally to oppose thumb toward center of palm and rotates it medially. (this action is done by a combination of many muscles {not just this one} including the posterior deep muscles and the thenar muscles in the hand). Innervation Arterial Supply Deep branch of ulnar nerve (C8 and T1). NOT MENTIONED Deep palmer arterial arch IN THE SHEETS NOR IN THE SLIDES
1. adductor pollicis transverse head. 2.adductor pollicis oblique head. 3. deep palmar arterial arch. 4.Medial side of base of proximal phalanx of thumb. 4
Origin Posterior surface of middle 1/3 of ulna and interosseous membrane Insertion Action Base of distal phalanx of thumb). Extends distal phalanx of thumb at carpometacarpal and interphalangeal joints. Innervation Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) ulna Base distal phalanx of thumb Arterial Supply Posterior interosseous artery NOT MENTIONED IN THE SHEETS
Origin Insertion Action Innervation Arterial Supply Posterior surfaces of radius and interosseous membrane Base of proximal phalanx of thumb Extends proximal phalanx of thumb at carpometacarpal joint Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) Posterior interosseous artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES Base of proximal phalanx of thumb
Almost the same action: extend proximal\distal phalanx. And goes to Distal phalanx of thumb extensor pollicis B Revis = from Radius and goes to the base of Proximal phalanx of thumb. extensor pollicis Longus = from ulna and goes to the base of distal phalanx of thumb.
A gab between the Extensor Pollicis Longus & Extensor Pollicis Brevis, you can see it when you extend your thumb. Lateral = E. Pollicis Brevis Medial = E. Pollicis Longus Floor = scaphoid, styloid of radius. - Contains Radial Artery (you can feel the pulse here) They use this box for snuffing powdered drugs as *z3ot* (not sure about the name) which will cause sneezing in order to clear their chest.
Origin Insertion Action Innervation Arterial Supply Posterior surfaces of ulna, radius and interosseous membrane Base of 1st metacarpal Abducts thumb and extends it at carpometacarpal joint Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) Posterior interosseous artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES
Origin Insertion Action Innervation Arterial Supply Indicis = index finger (the insertion). Posterior surface of ulna and interosseous membrane. Extensor expansion of 2nd digit. Extends 2nd digit and helps to extend hand. Posterior interosseous nerve (C7 and C8), the continuation of the deep branch of the radial nerve (C7, C8) Posterior interosseous artery NOT MENTIONED IN THE SHEETS NOR IN THE SLIDES Located inferiorly at the posterior lower end of ulna
The action is extending index and helping in extending hand. So when you point your index on someone saying hey you!!,actually one of the muscles you are using is the extensor indicis muscle. Origin: Posterior surface of ulna (from inferior) Insertion: 2 nd digit (index).
Supinator NEW Origin Insertion Action Innervation Lateral epicondyle of humerus, radial collateral ligament, Annular ligament, supinator fossa, crest of ulna Lateral,posterior anterior surface of proximal 1/ 3rd of radius supination Deep branch of radial nerve (c7,c8)
Very deep muscle seen when u remove ED muscle.
Innervations of Anterior Compartment-Forearm Muscles Muscle Nerve Superficial Muscles Flexor digitorum superficialis Flexor carpi radialis Pronator teres Palmaris longus Flexor carpi ulnaris Deep Muscles Pronator quadratus Flexor pollicis longus Median Median Median Median Ulnar Median Median Flexor digitorum profundus Ulnar (med 1/2) Median (lat 1/2) So all of the anterior forearm muscles (superficial & deep) are innervated by the Median nerve,excpet for Flexor carpi ulnaris (superficial) and medial half of Flexor digitorum profundus (D eep) are both innervated by the U lnar nerve
SurfaceAnatomy of Upper Limb {what u see if u palpate the upper limb} : Muscles like; Biceps +Triceps brachii. Olecrenon Process. Medial and lateral Epicondyle. Cubital Fossa. Snuffbox. Carpal tunnel. Note: You can t palpate the brachioradialis, but you can feel it contracting when you flex your forearm on the arm.(try it! It s nice!!)
Surface Anatomy of Upper Limb (continue) : Carpal Tunnel Carpals concave anteriorly Carpal ligament covers it Contains:long tendons, Median nerve Inflammation of tendons = compression of Median nerve Anatomical Snuffbox Lateral = E. pollicis brevis Medial = E. pollicis longus Floor = scaphoid, styloid of radius Contains Radial Artery (u can feel the pulse here).
NEW Carpel tunnel It s a tunnel formed between the concavity of the carpal bones and a ligament covers it which is the Flexor retinaculam. Tendons of the flexors pass through, median nerve also passes through. It is considered a crowded tunnel.
Carpel Tunnel Syndrome NEW Carpal tunnel syndrome: Caused due to compression on the nerve in the tunnel. Causes are : 1. Swelling of the tendon (overuse). 2. Pregnancy (edema) 3. Arthritis Symptoms: tingling or numbness in the lateral part of the hand, weakness in the thumb movement. Treatment: rest, splinting, antiinflammatory drugs, Surgery (according to the doctor is the best method).
It s a triangle in the anterior surface of elbow,with an imaginary line that passes between the epicondyles,and two muscles(pronator teres & Brachioradialis) which form the boundaries of this triangle. Boundaries: Medial= Lateral border of Pronator teres: sometimes Flexor C arpi Radialis overlaps pronator teres so we consider it as a medial boundary for the fossa. Lateral= Medial border of Brachioradialis. Superior= Imaginary Line between epicondyles.
Contents of the cubital fossa: Median CubitalVein. BrachialArtery. Median Nerve. -Intheposterioraspect of thehandthere are twoarches, the most effective is the superficial venous arch, this arch goes medially&laterally with2 veins(the cephalic&basilic veins), these twoveins will go up to thecubital fossa andgive collateral branches(called median cubital veins), thesebracheswill form H, Mor Nshape. (M shape is the most common) - Fromhere wecan draw the venous blood.
Branch of the radial nerve coming anteriorly from the posterior compartment. The biceps tendon diverges toward the radial end where the bicipital aponeurosis covers the pronator teres muscle,overlapping it,and goes away to the ulnar bone. Sometimes replaced by the Flexor Carpi Radialis muscle. Doctors measure the blood pressure of the brachial artery in the cubital Fossa. NEW
NEW 2) Between the pronator teres ad biceps brachii and Directly beneath the bicipital aponeurosis lays the brachial artery (important for pulse detecting) 1) The apex of the imaginary triangle is at the meeting point between brachioradials and pronator teres 3) Medially to the brachial artery is the median nerve. It leaves the fossa by passing between the ulnar and humeral heads of the pronator teres muscle.
The major three contents of the cubital fossa : 1) Brachial artery 2) Median nerve 3) Median cubital vein NEW
NEW Surface anatomy of cubital fossa Right underneath the skin and medially is the median cubital vein, it is posterior to the bicipital aponeurosis So the arrangement is (anterior to posterior) 1) Skin and superficial fascia 2) Median cubital vein 3) Bicipital aponeurosis 4) Brachial artery and median nerve
Roof of cubital fossa: The roof of the cubital fossa is formed by superficial fascia and skin. NEW The superficial contents of the cubital fossa: 1 median cubital vein (most important) 2 medial and lateral antebrachial cutaneous nerves 3 basilic and cephalic veins.
NEW The deep contents of the cubital fossa: 1) The tendon of the biceps brachii muscle; 2) The terminal part of brachial artery, radial and ulnar arteries. 3) Radial nerve 4) (Deep) accompanying veins of the arteries
Radial nerve lies under brachioradialis (lateral margin of the fossa) gives off deep branch of the radial nerve and continues as superficial radial nerve. NEW The brachial artery normally bifurcates into the radial and ulnar arteries in the apex of the fossa, although this bifurcation may occur much higher in the arm, even in the axilla.